A tremendous amount of DNA sequence information is now available to scientists and engineers. These DNA sequences provide the foundation for studying how the genome of an organism is functioning and they are particularly useful for metabolic engineers interested in manipulating plants for the production of chemicals and enzymes. Functional genomics relies on high-throughput techniques for measuring the mRNA (the transcriptome), protein (the proteome), and metabolite (the metabolome) components of plants as well as their organs and tissues. Microarray technologies, recent advances in protein mass spectrometry, and high-throughput metabolite analyses are beginning to provide detailed information on the total mRNA, protein, and metabolite components of plants. This knowledge will allow scientists to monitor changes in proteins and metabolites in plants. Ultimately, it may allow them to discover new metabolic pathways and to model metabolic and regulatory networks in plants.